Unitary expansion valve and distributor mechanism



Jan. 24, 1939. 1. L. sHRoDE --2144898 UNI-TARY EXPANSION VALVE ANDDISTRIBUTOR MEGHANISM Filed April '7. 1938 FY7. Z. y I 26 2&6 n

273 J fr l Jlm L. .Shrads 1irt'exitcci Jan. 24, 1939 UNITARY EXPANSIONVALVE AND DISTRIBUTOR MECHANISM l John L. Shi-ode, Richmond Heights,Mo., assignor to Alco Valve Company, Incorporated, St.

Louis, Mo., a corporation of Missouri Application April 7, 1938, SerialNo. 200,791

11 Claims. (Cl. 62-127) This invention relates to refrigeration and hasfor its general object the provision of a unitary expansion valve anddistributor mechanism, the purpose of which is to effect thedistribution of liquid and gaseous refrigerant in homogeneous mixtureproportionately to a plurality of similarly or differently loaded coilpasses according to the needs of each and regardless of changes in the.

load or rate of flow of the refrigerant.

Up to the present invention an evaporator having a multiplicity of tubesand not intended for full flooded operation was usually supplied withrefrigerant by one of three methods, one being to connect all the tubesin series and to supply l the refrigerant through a single expansionvalve.

Another was to divide the evaporator into several multiple passesbeginning and terminating in inlet and outlet headers, the refrigerantbeing supplied to the inlet header by one expansion valve. The thirdmethod was to supply refrigerant to each pass by a separate expansionvalve, one to each pass.

None of these methods has proved entirely satisfactory. The first namedmethod brought about an extreme pressure drop between the inlet andoutlet ends of the evaporator resulting in loss in refrlgeratingcapacity. The second named method involved the employment of severaltypes of inlet headers, these being customarily classed either ascentrifugal or gravity headers. The centrifugal header was theoreticallyarranged so that the velocity and volume of refrigerant entering theheader would feed the required amount of refrigerant to each of theseveral passes connected to the header. With such an arrangement,reduction of refrigeration load which always occurs at times in anyevaporator would cause the expansion valve to throttle and the ow ofrefrigerant entering the centrifugai header would decrease, the resultbeing improper distribution and starvation of one or more passes.

The gravity header supplied theoretically equal feed to all passes dueto the existence of a static 4.5 uquid head in the header, but in theabsence of a static liquid head. that pass offering the least resistanceat the moment would receive the greater proportion of the refrigerantadmitted to the header by the expansion valve.

'I'he third named method overcame most of the objections to the firsttwo, but since it involved a valve for each pass, the cost ofinstallation is in general too great to make this method practicable.

55 It is therefore obvious that a single expansion valve so designed asto automatically supply the required proportion of refrigerant to eachof the several passes regardless of total load changes and resultantchanges in the rate of refrigerant ow, would eliminate the necessity ofinlet head- 5 ers as well as a multiplicity of valves, and would provideideal distribution.

With this and other objects in view, the present invention will bereadily understood by reference to the following specification andclaims 10 and to the drawing which accompanies and forms a part of thespecification and in which:

Figure 1 is a perspective view of a multi-pass evaporator and expansionvalve embodying the features of the invention; 15

Figure 2 is an axial section through the expansion valve and distributormechanism;

Figure 3 is a. cross section taken along the line 3--3 of Figure 2; and

Figure 4 is a section taken along the line 4-4 of Figure 3.

Referring now in detail to the several iigures, the numeral I representsas a whole the unitary expansion valve and distributor mechanism intowhich the inlet ends of the passes 2 are connect- 25 ed, theoppositeends of said passes being shown connected to a suction header 3. Thehigh pressure side of the system is represented by the pipe l, the lowpressure or suction side being designated by the pipe 5. 30

Referring to Figure 2 in which the details of the expansion valve anddistributor mechanism l are disclosed, the body 6 has a bore 1 to whichthe liquid refrigerant carrying pipe 4 is connected. The upper part ofthe body is expanded 35 to form a flange 8 which is recessed as at 9 toform a seat for the distributor head lli. Said distrlbutor head as shownis formed with an axial passage II and with a circumferential series ofradial passages I2 communicating with the axial 40 passage Il and lyingin the zone of the flange 8 of the body 6. Said flange is provided witha series of radial outlets I3 which register with the radialpassages I2in the distributor head, and a pin connection I4, shown in Figure 4, be-

-tween the distributor head and the ange 8 prevents relative rotationbetween the distributor head and. the body 6 and so keeps the passagesI2 in registry with the outlets I3.

In general, the passages I2 may be of similar 50 or different crosssectional diameter as shown in Figure 3 since proportionate distributiondepends upon the sizes of these passages. The outlets I3 are of like orlarger diameter than the diameters of the passages I2 so that theoutlets I3 55 shall not have a throttling effect upon said passages andreduce the velocity of ow through said passages.

A reciprocatory valve I5 is seated at the lower edge of the axialpassage I I, said valve as shown being provided with a cylindricalportion I6 which is slidabiy guided in that part of the axial passage II which is above the zone of the radial passages I2. The lower part ofthe axial passage II, that is to say, that part which extends from thevalve seat to the zone of the passages I2 is somewhat expanded forming avalve chamber II.

It is, of course, a. well known fact that as soon as an expansion valveopens, expansion takes place and the fluid immediately adiacent the lowside of the expansion valve usually becomes a mixture of liquid andgaseous refrigerant. The distribution of this mixture proportionatelythrough a plurality of passages is greatly simpliiled and materiallyenhanced by maintaining its liquid and gaseous constituents inhomogeneous mixture during the course of its distribution.

According to the present invention, the conduit constituted by the crosssection of the port of the valve I5 when said valve is open, the crosssection of the annulus constituting the valve chamber and the. crosssections of the several distributing passages I2 are so restrictedrelative to the velocity of flow of the refrigerant that its velocity isnot checked and consequently a homogeneous mixture of liquid and gaseousrefrigerant is delivered through the several passages I2 to the outletsI3 to which the several passes 2 of the evaporator are connected. 'I'hemaintenance of this homogeneous liquid and gaseous mixture is fosteredby the close adjacency of the passages I2 to the valve I5.

The rest of the structure illustrated in Figure 2 is common to knownexpansion valves. The valve I5 has a stem I5 with a ball end 20 whichrests in a spherical seat 2I in a plate 22 contacting the center of adiaphragm 23 in a diaphragm chamber formed between the iitting 24 andthe cap 25 between which fitting and cap the diaphragm edges are clampedor otherwise secured. The upper part of the diaphragm chamber isconnected by means of the tube 26 with the thermostatic bulb 2l appliedor inserted at the suction end of the evaporator. 'I'he lower part ofthe diaphragm chamber is connected by an external equalizer 28 directlywith the interior of the system at the suction end of the evaporator,said equalizer being connected into the chamber of the tting 24 by meansof a nipple 3U, and the chamber of the tting 24 being in communicationwith the lower part of the diaphragm chamber through the annular opening3|. The valve I5 is normally kept closed by a spring 29 which pressesupwardly against the ball end of the valve stem. Dominant differentialpressure on opposite sides of the diaphragm opens the valve against thepressure of the spring 29.

While the present illustrative embodiment of the invention shows thevalve-actuating means as being a diaphragm, it will be understood bythose skilled in the art that the present invention does notparticularly concern itself with the means for actuating the valve andthat known and conventional equivalent actuating devices may besubstituted for the diaphragm without transcending the spirit and scopeof the invention. In this connection, it may be stated also that aninternal equalizer may be substituted for the external equalizer ifdesired, and that any other device which is the equivalent of thethermostatic element, for creating or transmitting force to the oppositeside of the diaphragm may be employed and still be within the scope ofthe invention.

Referring to Figure 1 of the drawing, it is assumed that the evaporatortherein shown is employed for air conditioning and that the current ofair is owing in the direction of the arrow. It is obvious that the coilpass 2a carries the heaviest load, for the air is at its highesttemperature when it impinges upon this pass while it has becomeprogressively cooled as it flows from one pass to the other. It followstherefore that the pass 2a should receive the greatest amount ofrefrigerant. It is therefore connected as shown in Figure 3 to thepassage I2 having the greatest diameter. Likewise, the coil 2b being atthe rear of the coil, carries the least load and is therefore connectedas shown in Figure 3 to the distributing passage I2 which has thesmallest diameter. Although air is indicated in this discussion, theprinciple is applicable to any other fluid.

In this invention correct proportional distribution is assured not onlywhen the main throt- -tling valve is in its extreme open position, but

also throughout the entire flow range of the valve. Throttling the valveI5 equally throttles the flow to each of the distributor passages, andbecause of the fixed position of the distributor passagesA with relationto the outlets I3 from the valve body, and because of the closeproxlmity of each to the other and to the main throttling valve andbecause of the high jet velocity thus maintained, changes in flowthrough the valve I5 are correspondingly reilected in the flow to eachoutlet without interfering with the proportional distribution.

While I have in the above description disclosed what I believe to be apreferred and practical embodiment of the invention, it will beunderstood to those skilled in the art that the speciilc details ofconstruction and arrangement of parts as illustrated and described areby way of example and not to be construed as limiting the scope of theinvention as defined in the appended claims.

What I claim is:

1. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore one end of which is adapted to communicate with thecondenser of a refrigeration system, an expansion valve member insaidbore defining with the walls of said bore a valve chamber on the side ofsaid valve member remote from said one end, said body being providedwith lateral distributing passages opening into said valve chamber,adapted to be connected to the inlet ends of coil passes.

2. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore one end of which is adapted to communicate with thecondenser of a refrigeration system, an-expansion valve member in saidbore defining with the walls oi said bore a valve chamber on the side ofsaid valve member remote from said one end, said body being providedwith lateral distributing passages opening into said valve chamberadapted to be connected to the inlet ends of coil passes, the conduitconstituted by the valve port when the valve is open, said valve chamberand said distributing passages being of cross-sectional area sorestricted as to maintain such velocity of flow as to maintain theliquid and gaseous refrigerant in homogeneous mixture until it reachessaid passes.

3. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore one end of which is adapted to communicate with thecondenser of a refrigeration system, an expansion valve member in saidbore defining with the walls of said bore a valve chamber on the side ofsaid valve member remote from said one end, said body being providedwith lateral distributing passages opening into said chamber,terminating at their ends remote from said valve chamberin outlets of atleast as great a diameter as that of said passages, adapted to beconnected to the inlet ends of coil passes.

4. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore one end of which is adapted to communicate with thecondenser of a refrigeration system, an expansion valve member in saidbore defining with the walls of said bore a valve chamber on the side ofsaid valve member remote from said one end, said body being providedwith lateral distributing passages of diilerent cross-sectional areasopening into said valve chamber, said passages terminating in outlets ofat least as great a diameter as that of said passages, adapted to beconnected to the inlet ends of coil passes.

5. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore one end of which is adapted to communicate with thecondenser of a refrigeration system, an expansion valve member in saidbore, said body being provided with radial distributing passages openinginto said bore on the side of said valve member remote from said one endand closely adjacent thereto, said passages being adapted to beconnected to the inlet ends of coil passes.

6. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore adapted to be connected to the condenser of arefrigeration system, said body including a distributor head seatedwithin a recess in said body, said distributor head having a valvechamber communicating with said bore and a plurality of distributingpassages opening radially into said valve chamber, a valve seating onsaid distributor head to control the passage of liquid refrigerant fromsaid bore to said valve chamber, said body having outlet passagesregistering with the distributing passages of said distributor head andof at least as great a cross sectional area as that of said passages.

'7. Unitary expansion valve and distributor mechanism comprising a bodyhaving abore adapted to be connected to the condenser of a refrigerationsystem, the upper end of said body having a recess communicating withsaid bore and having radial outlets with their inner ends opening in theWalls of said recess, a distributor head iitting in said recess having avalve chamber communicating with said bore and having radialdistributing passages communicating with said valve chamber and withsaid outlets, said distributing passages being not larger in crosssection than said outlets, a reciprocable valve seating on said,distributor head and controlling communication between said bore andsaid valve chamber, and means for actuating said valve.

8. Unitary expansion valve and distributor mechanism comprising a bodyhaving av bore adapted to be connected at one end to the condenser of arefrigeration system, a distributor head carried by said body having avalve chamber communicating with said bore and having radialdistributing passages communicating at their inner ends with said valvechamber, said body having radial outlets in registry with the outer endsof said distributing passages and of at least as large a diameter asthat of said passages, a reciprocable valve member seating on saiddistributor head and controlling communication between said bore andsaid distributing passages, and means for actuating said valve member.

9. In an expansion valve mechanism of that type in which the control ofthe supply of liquid refrigerant to an evaporator in a refrigerationsystem is eiected by a iluid pressure actuated valve responsive torefrigerative requirements of the evaporator, a body having a boreadapted to be connected to the condenser of said refrigeration system,an expansion valve member in said bore, said body being provided withradial distributing passages opening into said bore on the side of saidvalve member opposite said condenserand closely adjacent to said valvemember, said passages being adapted to be connected to the inlet ends ofthe passes of such evaporator.

10. In an expansion valve mechanism of that type in which the control ofthe supply of liquid refrigerant to an evaporator in a refrigerationsystem is eiected by a fluid pressure actuated valve responsive torefrigerative requirements of the evaporator, a body having a boreadapted to be connected to the condenser of said refrigeration system, adistributor head unitarily mounted with respect to said body having avalve chamber communicating with said bore and having radialdistributing passages communicating with said valve chamber, said bodyhaving radial outlets registering with the outer ends of said dis-ktributing passages and being of at least as large cross-sectional areathan the cross-sectional areas of said passages, said outlets beingadapted to be connected to the inlet ends of the passes of saidevaporator, and a reciprocable valve seating on saiddistributor head andcontrolling communication between said bore and said valve chamber.

11. Unitary expansion valve and distributor mechanism comprising a bodyhaving a bore adapted to be connected to the condenser of arefrigeration system, the upper end of said body having a recesscommunicating with said bore and having radial outlets with their innerends opening in the walls of said recess, a distributor head fitting insaid recess having a valve chamber communicating with said bore andhaving radial distributing passages communicating with said valvechamber and with said outlets, the latter being adapted to be connectedto the inlet ends of the passes of an evaporator coil, said distributingpassages being not larger in diameter than said outlets, a reciprocablevalve seating on said distributor head and controlling communicationbetween said bore and said valve chamber, means for actuating saidvalve, said distributor head being formed with a guide and said valvehaving a portion slidable in said guide.

JOHN L. SHRODE.

